Evaluation on the Pathogenesis of Streptococcus agalactiae in Nile Tilapia (Oreochromis niloticus)

Pretto‐Giordano, Lucienne Garcia; Müller, Ernst Eckehardt; Freitas, Júlio César de; Silva, Vanessa Gomes da

doi:10.1590/s1516-89132010000100011

Cited by 59 publications

(23 citation statements)

References 20 publications

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“…The present study explored the susceptibility and pathogenesis of Queensland grouper to infection by GBS via different routes of exposure and in order to fulfil Koch's postulates and confirm the previous hypothesis that S. agalactiae was causative for the wild fish mortality. Previous studies have demonstrated the susceptibility of Nile and red tilapia to virulent GBS isolates in experimental injection trials (Evans et al , 2004Chen et al 2007;Inocente Filho et al 2009;Pretto-Giordano et al 2010;Abuseliana et al 2011). Interestingly, of the two surviving fish from the injection challenge trial (10 3 cfu fish À1 ), only one fish had gross clinical signs of bacterial infection (bilateral exophthalmos and a congested anus), but both were PCRpositive, and histopathology showed Gram-Glynnpositive bacteria in stained tissues.…”

Section: Immunohistochemistry On Queensland Grouper Tissuesmentioning

confidence: 95%

Infection and pathology in Queensland grouper, Epinephelus lanceolatus, (Bloch), caused by exposure to Streptococcus agalactiae via different routes

Delamare-Deboutteville

Bowater²,

Condon³

et al. 2014

Journal of Fish Diseases

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Since 2007, 96 wild Queensland groupers, Epinephelus lanceolatus, (Bloch), have been found dead in NE Australia. In some cases, Streptococcus agalactiae (Group B Streptococcus, GBS) was isolated. At present, a GBS isolate from a wild grouper case was employed in experimental challenge trials in hatchery-reared Queensland grouper by different routes of exposure. Injection resulted in rapid development of clinical signs including bilateral exophthalmia, hyperaemic skin or fins and abnormal swimming. Death occurred in, and GBS was re-isolated from, 98% fish injected and was detected by PCR in brain, head kidney and spleen from all fish, regardless of challenge dose. Challenge by immersion resulted in lower morbidity with a clear dose response. Whilst infection was established via oral challenge by admixture with feed, no mortality occurred. Histology showed pathology consistent with GBS infection in organs examined from all injected fish, from fish challenged with medium and high doses by immersion, and from high-dose oral challenge. These experimental challenges demonstrated that GBS isolated from wild Queensland grouper reproduced disease in experimentally challenged fish and resulted in pathology that was consistent with that seen in wild Queensland grouper infected with S. agalactiae.

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Section: Immunohistochemistry On Queensland Grouper Tissuesmentioning

confidence: 95%

Infection and pathology in Queensland grouper, Epinephelus lanceolatus, (Bloch), caused by exposure to Streptococcus agalactiae via different routes

Delamare-Deboutteville

Bowater²,

Condon³

et al. 2014

Journal of Fish Diseases

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“…Os sinais clínicos incluem anorexia, escurecimento da pele, natação errática, letargia, curvatura do corpo, exoftalmia e opacidade de córnea uni ou bilateral, sufusões no opérculo e base das nadadeiras, ulceração da epiderme e morte (TRABULSI; ALTERTHUM, 2008). As lesões internas são caracterizadas por congestão brânquial, hepatomegalia acompanhada de congestão, ascite, esplenomegalia e encefalomalácia (SALVADOR et al, 2003;FIGUEIREDO et al, 2006;PRETTO-GIORDANO et al, 2010).…”

Section: Introductionunclassified

Isolamento de Streptococcus agalactiae em diferentes órgãos de tilápias do nilo (Oreochromis niloticus) criadas em tanques-rede

Marcusso¹,

Eto²,

Claudiano³

et al. 2015

Biosci. J.

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RESUMO:A estreptococose é uma das principais causas de mortalidade na criação de tilápias no Brasil, causando grandes perdas econômicas. Assim, o estudo objetivou determinar a frequência de isolamento e identificação por PCR de Streptococcus agalactiae em diferentes órgãos de tilápias do Nilo (Oreochromis niloticus) naturalmente infectadas, oriundas de oito pisciculturas da região norte do estado do Paraná que apresentavam sinais clínicos característicos de infecção estreptocócica. Para tanto, coletaram-se amostras de sangue e fragmentos de rim, fígado, baço, coração e encéfalo. Essas foram semeadas em meio ágar infusão de cérebro e coração (BHI) adicionado 5% de sangue de ovino e incubados à 29ºC, durante 7 dias em aerofília. Após o crescimento bacteriano e a partir das características macro e microscópicas, foram selecionadas colônias compatíveis com as do gênero Streptococcus sp.. As espécies foram identificadas através de PCR e confirmadas por meio do sequenciamento do gene 16S rDNA. Os resultados demonstraram que em tilápias do Nilo infectadas com S. agalactiae, o isolamento é mais frequente em encéfalo, rim e fígado em ordem decrescente.

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“…External analysis showed clinical signs of disease, foremost among them skin hemorrhages, corneal opacity, body ulceration, liver discolouration, frayed fins and intestine and vesicle inflammation, these abnormalities are considered as the main symptoms of infection reported by Giordano, et al [17,26,27], who observed signs such as skin alterations, anorexia, exophthalmia, corneal opacity, extension of the visceral cavity, bleeding and abdominal inflammation, hepatomegaly and splenomegaly. According to Soto [28] it is proven that bacteria are the cause of epithelial hyperplasia in gills, splenomegaly, renomegaly and necrosis in internal organs, mainly in spleen, heart, liver, kidney, brain and musculature.…”

Section: Discussionmentioning

confidence: 89%

“…It has a prevalence of 40% and 70% in stages of fry, juvenile and fattening. It is also reported in several species of fish around the world, due to its geographic distribution includes regions with temperate and tropical climate, as presented by Brazil, China, Malaysia and the United States [16][17][18]. Some diseases are caused by not applying sanitary protocols on growing farms, as well as the use of antibiotics as an almost mandatory preventive or corrective practice.…”

Section: Introductionmentioning

confidence: 99%

Pathogenic Bacteria in Oreochromis Niloticus Var. Stirling Tilapia Culture

Zg¹,

Mr²,

Lango-Reynoso³

2017

Fish Aquac J

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Tilapia Oreochromis niloticus is an aquaculture resource that represents one of the most popular crops in the world. However, species cultivation presents health problems, which are associated with the presence of pathogenic bacteria and causes high economic losses. The aim of this study was to determine the diversity of these bacteria at the genus level in the species O. niloticus var. Styrling during growing stage in the fattening and pre-fattening phases. Tilapia samples were collected and analyzed; each sample was subjected to a macroscopic external and internal observation of organs and tissues. Subsequently, samples were evaluated by microbiological tests using Trypticase Soy Agar (TSA), Thiosulfate Citrate Bile Salts Sucrose Agar (TCBS) and selective media (Pseudomonas sp. Group), and conventional biochemical tests aimed at the production of glucose, sucrose, lactose, oxidase, catalase, indole, ornithine and Gram staining. External analysis revealed clinical signs of disease such as skin bleeding, body ulceration, corneal opacity, and intestine and vesicle inflammation. Microbiological and biochemical analysis showed the presence of eleven bacterial genera known as Arthrobacter sp., Enterococcus sp., Staphylococcus sp., Micrococcus sp., Streptococcus sp., Aeromonas sp., Pseudomonas sp., Edwardsiella sp., Flexibacter sp. and Flavobacterium sp., with a predominance of 55% Gram-negative bacilli in tilapia crops. According to the results, it is necessary to take preventive and corrective measures in order to avoid possible risks during production cycles, mainly when handling organisms. It is also important to promote good crop management practices and quality systems in production units to benefit the aquaculture sector.

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Evaluation on the Pathogenesis of Streptococcus agalactiae in Nile Tilapia (Oreochromis niloticus)

Abstract: The pathogenesis of a Streptococcus agalactiae was evaluated in a three-period experiment. Two groups of 40 fishes were intraperitoneally (i.p.)

Cited by 59 publications

References 20 publications

Infection and pathology in Queensland grouper, Epinephelus lanceolatus, (Bloch), caused by exposure to Streptococcus agalactiae via different routes

Infection and pathology in Queensland grouper, Epinephelus lanceolatus, (Bloch), caused by exposure to Streptococcus agalactiae via different routes

Isolamento de Streptococcus agalactiae em diferentes órgãos de tilápias do nilo (Oreochromis niloticus) criadas em tanques-rede

Pathogenic Bacteria in Oreochromis Niloticus Var. Stirling Tilapia Culture

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